Gravity induced flow liquid level regulators adapted to maintain a desired liquid level in a liquid containing sump are generally comprised of an air tight, refillable liquid reservoir positioned above the sump, a liquid flow or supply conduit connected between a lower portion of the reservoir and the sump to conduct liquid to the sump and a gas flow or sensing conduit which terminates at one end in fluid flow communication with a gas, generally air, containing space above the liquid level in the reservoir and terminates at its other end at the desired level at which liquid is to be maintained within the sump.
Such liquid level regulators are essentially barometric systems in which the flow of liquid from the reservoir to the sump is controlled by the pressure differential existing between the atmospheric or air pressure exerted on the liquid in the sump and the air pressure present above the oil level in the reservoir.
In such regulators liquid can flow, induced by gravitational force, from the reservoir to the sump through the supply line as long as air can flow through the sensing conduit into the air containing space above the liquid level in the reservoir. When the liquid level in the sump is at the desired level the liquid covers and seals that end of the sensing conduit within the sump and prevents the flow of air to the reservoir. As liquid continues to flow through the supply line a partial vacuum is formed in the air containing space above the liquid in the reservoir. The liquid ceases to flow when the flow inducing gravitational force exerted on the liquid is equalized by the partial vacuum above the liquid, or, barometrically speaking, when the pressure differential between the air pressure on the surface of the liquid pool in the sump and the air pressure on the surface of the liquid in the reservoir equals the head of liquid in the supply line.
When the liquid level in the sump falls below its desired level the end of the sensing line is uncovered to enable air to flow to the reservoir, causing a decrease in the partial vacuum, i.e. an increase in air pressure, and a consequent flow of oil until the end of the sensing line is again sealed by the liquid. Thus, as long as the reservoir has liquid in it, the desired level of liquid is maintained in the sump.
Such regulators have long been used in attempts to maintain the oil in the crankcase of an engine at a desired level and much prior art effort has been expended to increase the accuracy of such regulators by decreasing false oil level sensings resulting from oil movement or slosh upon movement and tilting of engines, such as those in vehicles.
However, the inventor of this invention has discovered that many of the false oil level sensings of the air carrying conduits of such regulators result from violent gas or air currents caused by the moving components of the engine and/or by gases entrained in the oil, generally in the form of small bubbles.